Consider this slightly different scenario. The party finds the entrance to a vault. In front of the vault is a pile of the dry, desiccated bodies of a previous group of adventurers. As a last act, one of previous group wrote in their own blood, "Death is waiting behind the door." One way to make the scenario even more interesting is to include a scroll of Speak with Dead among the effects of the dead adventurers.
Clive Barker wrote a short story called "The Inhuman Condition". The plot involves a rope with three knots. Untying a knot unleashes a supernatural beast. A big knot of string holds the vault door closed instead of a complex lock. Scrawled in dried blood is "Don't untie the knot!" The party is now faced the same problem as Alexander the Great when the Phrygians presented him Gordian knot.
When the party opens the vault, the find only a dark green beret monogrammed with the name Julian, a single copper coin, and a note. Written with fine calligraphy the note says, "I left a coin for your trouble."